Uggghhh why is writing so hard now?

I used to be able to write tons in middle school and make new ideas for stories. I remember writing a Whole book (was not a super long one it had like 8 chapters that consisted of 2-3 pages each) and now it's just so God damn hard...eventually as I got older it had become harder, I started getting tons of writers block and just not finishing what I started. I got to a point of bailing on all my work, And pretty much ending the works with an author's note saying that I would no longer be able to continue writing a work because of lots of writers block and the struggle to try to figure out what comes next. (My works had been on a sharing app/site, so people got to read it and stuff.) Writing for some reason now just strains me, i feel like the cogs and gears in my mind just are stuck. Sure they'll move a bit sometimes, but like then I'll get stuck and they just won't move at all.